Photo-affinity labeling. II. Photolysis of amido derivatives of nitrophenyl azides.

Photolysis of some amido derivatives of nitrophenyl azides was studied. In most cases, the products isolated were azo compounds and primary amines formed via triplet nitrenes. However, an anthranil, an intramolecular insertion product of nitrene into the adjacent amido group, was a major product in the case of o-amidonitrophenyl azide. A quenching study using isoprene showed that anthranil is formed from a singlet nitrene. The reaction modes of the nitrophenyl azides and the applicability of the compounds as potential photoaffinity labels are discussed.